Perfree

JFinal-Enjoy模板引擎(四)
JFinal Template Engine 采用独创的DKFF(Dynamic Key Feature Forw...
扫描右侧二维码阅读全文
24
2019/02

JFinal-Enjoy模板引擎(四)

JFinal Template Engine 采用独创的DKFF(Dynamic Key Feature Forward)词法分析算法以及独创的DLRD(Double Layer Recursive Descent)语法分析算法,极大减少了代码量,降低了学习成本,并提升了用户体验。与以往任何一款java模板引擎都有显著的不同,极简设计、独创算法、极爽开发体验,从根本上重新定义了模板引擎。


JFinal模板引擎专为java开发者打造,所以坚持两个核心设计理念:一是在模板中可以直接与java代码通畅地交互,二是尽可能沿用java语法规则,将学习成本降到极致。

因此,立即掌握 90% 的用法,只需要记住一句话:JFinal 模板引擎表达式与java是直接打通的。摘至官方文档
由于该模板引擎达式与java是直接打通的,很多语法一看就明白了,所以直接上例子再配合官方文档进行阅读,立即就掌握了。

项目一览

此项目源码地址jfinal-demo-04-enjoy-Template

pom文件

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.perfree</groupId>
  <artifactId>jfinal-demo-04-enjoy-Template</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>war</packaging>
  
  <dependencies>
      <dependency>
        <groupId>com.jfinal</groupId>
        <artifactId>jetty-server</artifactId>
        <version>2018.11</version>
        <!--
            此处的 scope 值为 compile 仅为支持 IDEA 下启动项目
            打 war 包时需要改成 provided,以免将一些无用的 jar 打进去
        -->
    </dependency>
    
    <dependency>
        <groupId>com.jfinal</groupId>
        <artifactId>jfinal</artifactId>
        <version>3.5</version>
    </dependency>
  </dependencies>
  
  <build>
    <finalName>jfinal-demo-03-controller</finalName>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.6.1</version>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                    <encoding>UTF-8</encoding>
                    <!-- java8 保留参数名编译参数,支持 action 带参 -->
                    <compilerArgument>-parameters</compilerArgument>
                    <compilerArguments>
                        <verbose />
                    </compilerArguments>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" version="2.5">
  <display-name>jfinal-demo-04-enjoy-Template</display-name>
   <filter>
    <filter-name>jfinal</filter-name>
    <filter-class>com.jfinal.core.JFinalFilter</filter-class>
    <init-param>
        <param-name>configClass</param-name>
        <param-value>com.perfree.common.DemoConfig</param-value>
    </init-param>
  </filter>
  <filter-mapping>
    <filter-name>jfinal</filter-name>
    <url-pattern>/*</url-pattern>
  </filter-mapping>
  
</web-app>

DemoConfig

com.perfree.common包下DemoConfig类继承JFinalConfig:

package com.perfree.common;

import com.jfinal.config.Constants;
import com.jfinal.config.Handlers;
import com.jfinal.config.Interceptors;
import com.jfinal.config.JFinalConfig;
import com.jfinal.config.Plugins;
import com.jfinal.config.Routes;
import com.jfinal.core.JFinal;
import com.jfinal.template.Engine;
import com.perfree.controller.EnjoyController;

public class DemoConfig extends JFinalConfig {
    
    public static void main(String[] args) {
        JFinal.start("src/main/webapp", 80, "/",5);
    }
    
    @Override
    public void configConstant(Constants me) {
        me.setDevMode(true);
    }

    @Override
    public void configEngine(Engine me) {
    }

    @Override
    public void configHandler(Handlers me) {
        // TODO Auto-generated method stub

    }

    @Override
    public void configInterceptor(Interceptors me) {
        // TODO Auto-generated method stub

    }

    @Override
    public void configPlugin(Plugins me) {
        // TODO Auto-generated method stub

    }

    @Override
    public void configRoute(Routes me) {
        me.add("/", EnjoyController.class,"/");

    }
}

User

com.perfree.pojo包下User类

package com.perfree.pojo;

public class User {
    private String name;
    private Integer age;
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public Integer getAge() {
        return age;
    }
    public void setAge(Integer age) {
        this.age = age;
    }
    
}

EnjoyController

com.perfree.controller包下EnjoyController类继承Controller

package com.perfree.controller;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import com.jfinal.core.Controller;
import com.perfree.pojo.User;

public class EnjoyController extends Controller {
    
    public void index() {
        //传入对象
        User user = new User();
        user.setName("铁蛋");
        user.setAge(22);
        setAttr("user", user);
        
        //向前台传入数字,前台作判断是否等于1,若等于1,展示哈哈,等于0展示呵呵,其他啦啦啦
        setAttr("num", 1);
        
        //向前台传入map
        Map<String,String> map = new HashMap<>();
        map.put("key1", "value1");
        map.put("key2", "value2");
        setAttr("map", map);
        
        //向前台传入list
        List<String> list = new ArrayList<>();
        list.add("张三");
        list.add("李四");
        list.add("王二");
        setAttr("names", list);
        
        //向前台传入空值
        setAttr("para", null);
                
        render("/index.html");
        
    }
}

index.html

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>首页</title>
</head>
<body>
    <!-- 普通字符串展示 -->
    <h4>普通字符串展示:</h4>
         #("Hello~")<br>
         hello+2=#("hello"+2)<br>
         将hello前两个字母打印: #("hello".substring(0, 2))<br>
    <hr>
    
    <!-- 普通运算 -->
    <h4>普通运算:</h4>
        1+1=#(1+1)<br>
        1==1:#(1==1)<br>
        三元运算:#(1==1?"相等":"不相等")
    <hr>
    
    <!-- 从对象取值 -->
    <h4>从对象取值:</h4>
        #(user.name)
        #(user.age)
        #(user.getName())
        #(user.getAge())
    <hr>
    
    <!-- if条件判断 -->
    <h4>if条件判断: </h4>
        #if(num == 0)
            num等于0,呵呵
        #else if(num == 1)
            num等于1,哈哈
        #else
            num不等于0也不等于1,啦啦啦
        #end
    <hr>
    
    <!-- 循环从list取值,names为后台传来的参数 -->
    <h4>循环从list取值: </h4>
        #for(name:names)
            #(name)
        #end
    <hr>
    <!-- 从map取值 -->
    <h4>从map取值: </h4>
        key1: #(map["key1"])<br>
        key2: #(map.key2)<br>
        key1: #(map.get("key1"))<br>
        所有的key: #(map.keySet())<br>
        遍历map: 
            #for(key:map.keySet())
                #(map.get(key))
            #end
    <hr>
    
    <!-- 定义map并输出 -->
    <h4>定义map并输出: </h4>
        #set(myMap={"张三":22,"李四":21})
        #(myMap)<br>
        #(myMap.put("王二",20))
        #(myMap)<br>
    <hr>
    
    <!-- 空合并安全取值调用操作符 -->
    <h4>空合并安全取值调用操作符: </h4>
        #(para ??)它是空值
    <hr>
    
</body>
</html>

运行并访问


最后,该模板引擎表达式与Java是直接打通的,你能想到的,尽可以自己试验~官方文档地址

Last modification:February 25th, 2019 at 06:58 pm
If you think my article is useful to you, please feel free to appreciate

Leave a Comment